It is known to admix poly(glutarimides), especially those having residual acid and/or anhydride groups, and polyamides to prepare useful materials. It is further known to add impact-strength modifiers to such blends. It is further known to blend polyamides with poly(olefins) containing amine-reactive functional groups, and to blend polyamides with core/shell impact-strength modifiers containing amine-reactive functional groups in the shell.
Since the earlier discovery of thermally stable poly(glutarimides) and a process for their preparation by reacting an acrylic polymer with anhydrous ammonia or an anhydrous primary amine in a devolatilizing extruder, such polymers, especially those prepared by the treatment of poly(methyl methacrylate) with monomethylamine, have been employed as clear glazing or protective materials having acceptable impact strength and tensile modulus properties and a higher service temperature than most clear thermoplastics. Such poly(glutarimides) are also useful in blends with other thermoplastics, such as poly(vinyl chloride). Although the formation of graft copolymers upon admixture in the melt of such polyamides and poly(glutarimides) is not taught, I have discovered evidence that such graft formation occurs.
An object of the present invention is deliberately to prepare graft copolymers of polyamides and poly(glutarimides), and further to increase the efficiency of the grafting process to form a high percentage of graft copolymer with respect to the ungrafted polyamide and poly(glutarimide). A further object is to prepare polyamide-grafted poly(glutarimide) ionomers and clear, tough polymer blends of polyamides, poly(glutarimides) and polyamide-grafted poly(glutarimide) ionomers. Further objects of the invention will be apparent from the following specification and claims.